This adds new image files which come with a DRAM FIFO. The addition of
an N320 image with a DRAM FIFO allows DDR3 BIST to be run on an
assembled (motherboard + daughterboard) N320.
This image is intentionally very similar to the N300_AA and N310_AA
targets which serve the same purpose of providing an image with a DRAM
FIFO for their respective devices.
Original-commit: ae2b9bf7aeea6f8f98f6dacffdfc018d87107927